Telephone and telegraph transmitting apparatus.



H. SHOEMAKER. TELEPHONE AND TELEGRAPH TRANSMITTING APPARATUS.

APPLICATION FILED JULY 25, 1908.

932,821. Patented Aug. 31, 1909;

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UNITED STATES PATENT OFFICE.

HARRY SHOEHQHR, 0F J'ERS EY CITY, NEW JERSEY, A SSIGNOR T0 INTERNATIOIIAI, TELE: GRAPH CONSTRUCTION COMPANY, A CORPORATION'OF NEWYOBK.

. TELEBHONE AND TELEGRAPH TRANSMITTING APPARATUS.

Specification of Letters Patent. 7 Patented Aug. 31, 1909.

Application filed July 25, 1908. Serial No. 445,294.

' To all whom it may concern:

'Be it known that I, HARRY SHOEMAKER,

a citizen of the United States, residing in Jersey City, county of Hudson, State of New Jersey, have invented certain new and useful Improvements in Telephone and Telegraph Transmitting Apparatus, of which the following is a specification.

My invention relates to transmitting apparatus for telephone, telegraph or other signaling systems, and particularly those wherein the message or signal is transmitted through the natural media in electro-radiant form, as by electromagnetic waves.

It is the object of my invention to provide transmitting apparatus in which a high wave train frequency, higher than the limit of audition in-the case of a telephone. system,

may be secured, an oscillation circuit I of.

high natural frequency being provided to producehigh frequency energy to be radiated, and it is the object of my invention, in such a system, to secure the radiation of large amounts ofenergy which may be easily and simply controlled either by the voice,- telegraphic key, or ,other instrumentality.

More particularly it is the object of my in vention to supply an oscillation circuit with energy fluctuating or alternating at high rate, though at a rate lower than the natural frequency of the oscillation circuit, the alternatin g .or fluctuating energy being derived paratus for use in transmitting speech. Fig.

2 is a diagram of telephonic transmitting apparatus, the telephone transmitter being shown in various positions with relation tothe circuits. v Referring to Fig. 1, G is a source of elec- 'trical energy, either alternating or direct current (though preferably direct current) of .any suitable voltage, preferably low.

voltage. I The current is supplied from the generator G through the adjustable non-inductive resistance R and through the two adjustable inductances Z and l to the electrodes c and 0, between .which an arc is,

maintained. The inductances Z and Z may serve to prevent oscillations running back beyond the arc toward or to, the generator G, and they, or either of them, may also serve as a source of self-induction to give electromagnetic inertia to the circult contaming generator G and the arc. The are electrodes 0 and a may beof carbon or metal,

or any other suitable material, or one. electrode maybe of one material while the other electrode is of another material. And furthermore, the arc may be maintained in any suitable atmosphere as of hydrogen, steam, or hydro-carbons, etc., or maybe maintained in air. In shunt to the are, between the electrodes 0, c, is connected a circuit containing the variable condenser C, the primary? of a transformer, and the primaryof a small transformer. The primary i may serve as the principal inductance source of this circuit, and may be variable in number of turns or amount, or an addltlonal external variable inductance N may be em ployed. The number of turns in the primary 39 may also be adjusted as may also the number of turns in its secondary s, in circuit with which isconnected the telephone transmitter T, which may be the ordinary carbon micro hone transmitter, or of any other suitab e type. The secondary S is associated with the primary P, the two constituting, preferably, a step-up transformer, so that the secondary delivers current at higher potential than the current flowing through the primary. The number of turns in the secondary S may be adjusted and the distance of the secondary S from the primary P may be varied so that the coupling may be either a close one, or a loose one, though a close coupling is preferred. Connected across the secondary S is an adjustable condenser K which is connected in circuit with the spark gap 9 (preferably a small gap in the case of a telephonic transmitter) and a variable portionof the inductance L is also connected inand the earth or other connection E. The

amount of capacity and inductance in the V higher than the limit of audition. The ohmic resistance ofthe circuit containingO and P should be maintained low and should preferably not exceed ,two ohms, more or less.

By speaking into the telephone transmitter, T, the resistance of the circuit of the small secondary s is varied by and in accordance with speech and, in consequence,

the load upon the primary p varies also by and in accordance with speech, thus modifying the energy in the circuit C P aceord ingly. The high frequency current is transformed by the transformer P S and the condenser K 1s charged at a corresponding rate, and when charged, dlscharges across the gap 9 and through the inductance L producing high frequency oscillations as, for example, two hundred thousand per second or even a million. per second, more or less. Accordingly, in the well known manner the energy is radiated from the conductor A and is mOdifiedEby and in accordance with speech uttered at the transmitter T.

At the receiving station, which may be suitably attuned to the circuit containing battery with potentiometer .and telephone receiver. In the telephone receiver speech spoken into the transmitter T at the transmitting station will be reproduced. Or a primary celldetector may be employed suitably associatedhwith an aerial receiving conductor, an ordinary magneto or other telephone receiver being affected by the primary cell detector to reproduce speech.

Obviously, the apparatus shown in Fig. 1 may also serve for telegraphic or other purposes. For telegraphy an ordinary opera tors key is may be substituted in place of iss the primary p in the circuit C P. Or the key may be interposed in the oscillation circuit K, g, L or at any other suitable oint.

Refenring to Fig. 2, the generator resistance R, and inductances Z, Z and the are electrodes 0, c are the same as described in connection with Fig. l. A carbon micro-' hone or other telephone transmitter T may e inserted directly in series in the circuit containingC and P. As previously pointed out, the .resistance ,of this circuit containing C and P should be low and should preferably not exceed two ohms, more or less. In such case, the telephone transmitter T forms a substantial part of the entire resistance of such-circuit and, in response to speech or sound waves, changes the resist-. ance of that circuit materially. Or the telephone transmiter T may be inserted between the secondary S of'the preferably step-up transformer and the condenser K of the oscillation circuit similar to that shown in Fig. 1. Or the telephone transmitter may be inserted in the aerial conductor as shown at T, at the base of the conductor as shown, or at'anybthcr suitable point in the conductor or in the inductance L. Or a magnet core m may be disposed with its pole near the are and surrounded by a winding w included in circuit with a battery B and a telephone transmitter T. preferably laminated or composed of wires, and the resistance of the winding 'w should be relatively low so that the variations of resistance in the transmitter T will cause a substantial variation in the magnetic field produced in the core 111.. Thus, speaking into the telephone transmitter T causes fluctuations in the magnetic field in which the arc is placed, such fluctuations corresponding with speech or sound waves, the arc is influenced by and in accordance with speech,

thus changing the energy'in the circuit C P and the circuits supplied therefrom. It is preferredalso that the winding w have as low self-induction as possible consistent with securing sufficiently powerful magnetic field. Thus, I have shown in Fig. 2, four telephone transmitters T, any one of whichmay be employed when the others are omitted. Or, in some instances, two or more of them may simultaneously be used.

Obviously, in place of any of the telephonetransmitters shown in Fig 2, an ordinary telegraph key may be inserted so as to control the radiated energy to represent dots and dashes.

What I claim is:

1. In transmitting apparatus, an are, means for supplying current thereto, a circuit including said are, capacity and inductance, and having a natural frequency higher than the limit of audition, and means for deriving from the energy in said circuit high frequency oscillations, and a radiating conductor associated with said means.

2. In transmitting apparatus, an are, means for supplying current thereto, a circuit including said are, capacity and induct- The core m is ance, said circuit being adjusted for a. I

natural frequency higher than the limit of audition, an oscillation circuit, a step-up' natural frequency above the limit of audition, a high frequency oscillation circuit ,means for supplying current thereto, a cirv cuit containing said are, capacity and inductance, said circultbe ng ad usted for a deriving energy from said circuit, an asso ciated radiatin conductor, and a telephone transmitter inc uded in said first mentioned circuit.

4. In transmitting apparatus, an "are, means for supplying current thereto, a circuit including said arc, capacity and inductance, an oscillation circuit deriving energy from said circuit, the natural frequency of said oscillation circuit being higher than the frequency of said circuit containing the arc, and an associated radiating conductor.

5. In transmitting apparatus, a substantially continuously oscillating circuit having a relatively low natural period, a high frequency oscillation circuit associated with said first mentioned circuit and deriving energy therefrom, and an associated radiating conductor.

6. In transmitting apparatus, a substantially continuously oscillating circuit having a relatively lOW natural perlod, a high frequency oscillation circuit deriving energy from said first mentioned circuit, said second oscillation circuit including capacity inductance and a spark gap, and a radiating conductor associated with said second oscillation circuit.

*7. In transmitting apparatus, a substantially continuously oscillating circuit having a relatively low natural period above the limit of audition, a high frequency oscillaticncircuit including a spark gap associated with said first mentioned circuit and deriving energy therefrom, an associated radiator, and means for controlling the. radiated energy by sound Waves.

8. In transmitting apparatus, a substantially constantly continuously oscillating circuit having a relatively low natural period above the limit of audition, a high froqnency disruptive oscillation circuit deriving energy from said first mentioned circuit, a radiator, and means for controlling the radiated energy to represent a signal or message.

In testimony whereof I have hereunto affixed my signature in the presence of the two subscribing witnesses. I

. HARRY SHOEMAKER. Witnesses I DANIEL WEBSTER, Jr, ANNA E, STEINBOOK. 

